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| author |   John Hubbard <jhubbard@nvidia.com> | 2020-05-21 21:15:06 -0700 |
|---|---|---|
| committer |   Sam Ravnborg <sam@ravnborg.org> | 2020-05-31 22:54:37 +0200 |
| commit | 84be242dae81b36a4c696d8e7734f54d359e5cf3 (patch) | |
| tree | 0b30dcbaea394ab91184329f60d1f1da1318131a | |
| parent | video: fbdev: fix error handling for get_user_pages_fast() (diff) | |
| download | linux-dev-84be242dae81b36a4c696d8e7734f54d359e5cf3.tar.xz linux-dev-84be242dae81b36a4c696d8e7734f54d359e5cf3.zip | |
video: fbdev: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages*(), in a "Case 2" scenario
(DMA/RDMA), using the categorization from [1]. That means that it's
time to convert the get_user_pages*() + put_page() calls to
pin_user_pages*() + unpin_user_pages() calls.
There is some helpful background in [2]: basically, this is a small
part of fixing a long-standing disconnect between pinning pages, and
file systems' use of those pages.
[1] Documentation/core-api/pin_user_pages.rst
[2] "Explicit pinning of user-space pages":
https://lwn.net/Articles/807108/
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200522041506.39638-3-jhubbard@nvidia.com
| -rw-r--r-- | drivers/video/fbdev/pvr2fb.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c index ceb6ef590597..2d9f69b93392 100644 --- a/drivers/video/fbdev/pvr2fb.c +++ b/drivers/video/fbdev/pvr2fb.c @@ -652,7 +652,7 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf, if (!pages) return -ENOMEM; - ret = get_user_pages_fast((unsigned long)buf, nr_pages, FOLL_WRITE, pages); + ret = pin_user_pages_fast((unsigned long)buf, nr_pages, FOLL_WRITE, pages); if (ret < nr_pages) { if (ret < 0) { /* @@ -712,9 +712,7 @@ out: ret = count; out_unmap: - for (i = 0; i < nr_pages; i++) - put_page(pages[i]); - + unpin_user_pages(pages, nr_pages); kfree(pages); return ret; |